X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=README.md;h=30682951f15e1f6e793c08988c812761eeb769ec;hb=HEAD;hp=ecd58b56644b10ca7c9f1152aa67e161c7181002;hpb=b91c4ea256ef30ad191a450b02496a6542bb42eb;p=wasi-libc.git

diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1,48 +1,63 @@
-# WebAssembly Reference Sysroot
+# `wasi-libc`
 
-Caution: This is currently quite experimental and not generally usable yet!
+`wasi-libc` is a libc for WebAssembly programs built on top of WASI system
+calls. It provides a wide array of POSIX-compatible C APIs, including support
+for standard I/O, file I/O, filesystem manipulation, memory management, time,
+string, environment variables, program startup, and many other APIs.
 
-## What is this?
+`wasi-libc` is sufficiently stable and usable for many purposes, as most of the
+POSIX-compatible APIs are stable, though it is continuing to evolve to better
+align with wasm and WASI. For example, pthread support is experimentally
+provided via the [wasi-threads] proposal.`
 
-This is a "reference sysroot", which is meant to be part of a common C ABI
-that can be shared across C libraries and compilers. While it's intended to
-(eventually) be usable in its own right, we fully expect other
-implementations to be used in practice by many different systems, though
-we do hope that in those cases, this library defines a useful ABI that can
-be followed.
+[wasi-threads]: https://github.com/WebAssembly/wasi-threads
 
 ## Usage
 
-Obtain a WebAssembly-supporting C compiler, and then run:
+The easiest way to get started with this is to use [wasi-sdk], which includes a
+build of `wasi-libc` in its sysroot.
 
-```
-make WASM_CC=/path/to/wasm/supporting/c/compiler
+## Building from source
+
+To build a WASI sysroot from source, obtain a WebAssembly-supporting C compiler
+(currently this is only clang 10+, though we'd like to support other compilers
+as well), and then run:
+
+```sh
+make CC=/path/to/clang/with/wasm/support \
+     AR=/path/to/llvm-ar \
+     NM=/path/to/llvm-nm
 ```
 
-This makes a directory called "sysroot", by default. See the top of the Makefile
+This makes a directory called "sysroot" by default. See the top of the Makefile
 for customization options.
 
 To use the sysroot, use the `--sysroot=` option:
 
-```
+```sh
 /path/to/wasm/supporting/c/compiler --sysroot=/path/to/the/newly/built/sysroot ...
 ```
 
 to run the compiler using the newly built sysroot.
 
-## Why doesn't this contain a full libc implementation?
+Note that Clang packages typically don't include cross-compiled builds of
+compiler-rt, libcxx, or libcxxabi, for `libclang_rt.builtins-wasm32.a`,
+`libc++.a`, or `libc++abi.a`, respectively, so they may not be usable without
+extra setup. This is one of the things [wasi-sdk] simplifies, as it includes
+cross-compiled builds of compiler-rt, `libc++.a`, and `libc++abi.a`.
+
+## Building in pthread support
+
+To enable pthreads support via the [wasi-threads] proposal, follow the above
+build directions with one addition: `make ... THREAD_MODEL=posix`. This creates
+additional artifacts in `sysroot/lib/wasm32-wasi-threads` to support `--target
+wasm32-wasi-threads`.
 
-In the short term, one of the main goals is just to provide a reference
-point for people already maintaining their own libc codebases, to help
-reduce interface incompatibilities between the several different
-environments out there.
+## Arch Linux AUR package
 
-In the long term, there may some day be some form of standardized
-syscall/import layer for wasm which would could support a full
-"reference libc", at which point this repository might make sense as
-a place to host such a thing.
+For Arch Linux users, there's an official [wasi-libc] package tracking this Git
+repository. You might want to install other [WASI related packages] as well.
 
-In between, if there are specific pieces of libc functionality which
-people would find useful to have here, and which don't depend on any
-syscalls, we could add them, using code from existing third-party
-codebases as appropriate.
+[wasi-sdk]: https://github.com/WebAssembly/wasi-sdk
+[wasi-libc]: https://archlinux.org/packages/community/any/wasi-libc/
+[WASI related packages]: https://archlinux.org/packages/?q=wasi-